356 MR. F. E. BEDDARD ON [May 3, 



upon its salient characters, particularly those which bear upon its 

 affinities. 



The setae are strictly paired and show no noteworthy peculiarities ; 

 they are not in any way modified upon any segments of the body. 

 The clitellum occupies segments xiv. to xix. 



The alimentary canal is chiefly remarkable for two points : there 

 is a gizzard present, not a very usual occurrence with aquatic 

 Oligochaeta. The gizzard, moreover, is well developed ; it lies in 

 segment vii. 



In segment ix. are a pair of calciferous pouches ; these are com- 

 plicated in structure, being composed of a much-folded cellular 

 membrane. Although the segment which they occupy is the same 

 as that which in Ocnerodrilus contains a pair of oesophageal diver- 

 ticula, the organs are simpler in their minute structure in the latter 

 genus. 



Some of the anterior mesenteries, as is usually the case in Oligo- 

 chaeta, are thickened ; this statement applies to those which separate 

 segments v./vi., vi./vii., vii./viii., viii./ix. 



The nephridia are present in the genital segments ; the posterior 

 set are invested by a thick layer of peritoneal cells. 



The genital organs conform in almost every particular to the plan 

 met with in the genus Acanthodrilus, and are illustrated in the 

 accompanying drawing (woodcut, fig. 1). 



On segments xvii. and xix. are the openings of the atria ; the 

 actual pores are placed upon the summits of elevations near to the 

 median ventral line of the body. The atria, like those of other 

 Acanthodrilidae, are divisible into two regions : with the actual orifice 

 is connected a narrow muscular tube ; this widens out distally into a 

 glandular tube, but this glandular tube is lined by a single layer 

 only of cells. In no species of Acanthodi'iliis, so far as I am aware, 

 is this the case. Even in smaller species than the one described 

 here the glandular part of the atrium has two layers of cells, resem- 

 bling, as I have pointed out, the structure of the clitellum. On 

 the other hand, Ocnerodrilus has an atrium which is exactly like the 

 present species in having a lining of a single row of cells. These 

 cells are tall and very granular in appearance. The atrial pores are 

 close to the ventral pairs of setae ; there are no penial setae. Penial 

 setae are only rarely absent from Acanthodrilus ; A. multiporus and 

 an allied species are the only forms which I can recollect that are 

 thus deficient. 



On the xviiith segment open the vasa deferentia : there is only a 

 single vas deferens on either side ; it runs in close contact with the 

 body-wall, not embedded in it. In the xth segment the vas deferens 

 widens out to form a funnel ; this funnel is not only very large but 

 very much folded, and occupies the greater part of the segment in 

 which it lies. It struck me as being unusually large ; there is only 

 o^e funnel on each side. 



„ The same segment, i. e. the xth, contained the single pair of 

 testes. As a general rule, when there is a single pair of testes 

 these gonads occupy the xith and not the xth segment. In the 



